Sequential infiltration synthesis apparatus

ABSTRACT

The disclosure relates to a sequential infiltration synthesis apparatus comprising:
         a reaction chamber constructed and arranged to accommodate at least one substrate;   a first precursor flow path to provide the first precursor to the reaction chamber when a first flow controller is activated;   a second precursor flow path to provide a second precursor to the reaction chamber when a second flow controller is activated;   a removal flow path to allow removal of gas from the reaction chamber;   a removal flow controller to create a gas flow in the reaction chamber to the removal flow path when the removal flow controller is activated; and,   a sequence controller operably connected to the first, second and removal flow controllers and the sequence controller being programmed to enable infiltration of an infiltrateable material provided on the substrate in the reaction chamber. The apparatus may be provided with a heating system.

FIELD OF INVENTION

The present disclosure generally relates to apparatus and methods to manufacture electronic devices. More particularly, the disclosure relates to forming a structure on a substrate with an infiltration apparatus.

BACKGROUND

As the trend has pushed semiconductor devices to smaller and smaller sizes, different patterning techniques have arisen. These techniques include spacer defined quadruple patterning, extreme ultraviolet lithography (EUV), and EUV combined with Spacer Defined Double patterning. In addition, directed self-assembly (DSA) has been considered as an option for future lithography applications. DSA involves the use of block copolymers to define patterns for self-assembly. The block copolymers used may include poly(methyl methacrylate) (PMMA), polystyrene, or poly(styrene-block-methyl methacrylate) (PS-b-PMMA). Other block copolymers may include emerging “high-Chi” polymers, which may potentially enable small dimensions.

The patterning techniques described above may utilize an infiltrateable material, such as an EUV polymer or DSA block copolymer resist, disposed on a substrate to enable high resolution patterning of the substrate. To satisfy the requirements of both high resolution and line-edge roughness, the polymer resist may commonly be a thin layer. However, such thin polymer resists layer may have several drawbacks. In particular, high resolution polymer resists may have low etch resistance and may suffer from high line edge roughness. This low etch resistance and the high line edge roughness may makes the transfer of decent patterned to underlying layers more difficult.

It may therefore be advantageous to infiltrate an infiltrateable material, for example the patterned material resist, to alter the properties of the infiltrateable material. To perform infiltration of the patterned material it may be advantageously to have an optimized infiltration apparatus.

SUMMARY

In accordance with at least one embodiment of the invention there is provided a sequential infiltration apparatus comprising:

a reaction chamber provided with a substrate holder to hold at least one substrate;

a precursor distribution and removal system comprising one or more reaction chamber valves to provide to and remove from the reaction chamber a gaseous first and/or second precursor; and,

a sequence controller operably connected to the one or more reaction chamber valves and being programmed to enable sequential infiltration of an infiltrateable material provided on the substrate in the reaction chamber with the gaseous first and second precursor. The apparatus may be provided with a heating system constructed and arranged to control the temperature from the reaction chamber up to at least one of the reaction chambers valves to avoid condensation. The heating system may comprises heating elements to heat the reaction chamber and at least one duct between the reaction chamber and the reaction chamber valves to control the temperature from the reaction chamber up to at least one of said chambers valves. The temperature may be controlled to at least a boiling temperature of the first or second precursor at the pressure of the first or second precursor in the reaction chamber.

If a mixture of the first or second precursor with a mixing gas, such as for example an inert gas, is used the pressure of the first or second precursor in the reaction chamber may be the partial pressure of said precursor. The partial pressure may be the desired maximum pressure that may be reached during infiltration of the first and/or second precursor.

The speed of the infiltration process may increase with the (partial) pressure of the precursors. Processing at higher pressure may therefore be advantageously to maximize throughput but increases the risk of condensation on non-heated portions of the reaction chamber and any duct between the reaction chamber and the reaction chamber valves. By controlling the temperature of the gaseous first or second precursor in the reaction chamber up to the reaction chamber valves, the risk of condensation in the reaction chamber can be minimized.

The heating system may be constructed and arranged to control the temperature of the reaction chamber and a duct from the reaction chamber to at least one of the reaction chamber valves to between 20 and 450° C., preferably between 50 and 150° C., more preferably between 60 and 110 and most preferably between 65 and 95° C. The sequence controller may be constructed and arranged to reach and/or maintain a (partial) pressure of the first or second precursor in the reaction chamber between 0.001 and 1000 Torr, preferably between 0.1 and 400 Torr, more preferably between 1 and 100 Torr and most preferably between 2 and 50 Torr during infiltration.

In accordance with a further embodiment there is provided a sequential infiltration apparatus comprising:

a reaction chamber provided with a substrate holder to hold at least one substrate;

a precursor distribution and removal system comprising one or more reaction chamber valves to provide to and remove from the reaction chamber a gaseous first or second precursor; and,

a sequence controller operably connected to the one or more reaction chamber valves and being programmed to enable sequential infiltration of an infiltrateable material provided on the substrate in the reaction chamber with the gaseous first and second precursor. The apparatus may comprise a buffer tank provided in the precursor distribution and removal system.

The buffer tank may be positioned upstream the reaction chamber to store first or second precursor. The buffer tank may have a volume between 0.1 and 15, preferably between 0.3 and 3 and even more preferably between 0.5 and 2 times the volume of the reaction chamber. The buffer tank may be filled with the first or second precursor such that when the reaction chamber may be filled with said precursor it is more rapidly filled thereby increasing the throughput of the tool.

In accordance with yet a further embodiment there is provided a sequential infiltration synthesis apparatus comprising:

a reaction chamber provided with a substrate holder to hold at least one substrate;

a precursor distribution and removal system comprising one or more reaction chamber valves to provide to and remove from the reaction chamber a gaseous first or second precursor; and,

a sequence controller operably connected to the one or more valves and being programmed to enable sequential infiltration of a infiltrateable material provided on the substrate in the reaction chamber with the gaseous first and second precursor, wherein the apparatus comprises at least two reaction chambers each chamber constructed and arranged to accommodate a single substrate and the precursor distribution and removal system is a partially common precursor distribution to provide to and remove from the at least two reaction chambers the first or second precursor simultaneously.

By having at least two reaction chambers the throughput of the apparatus may be increased. By having a partially common first or second precursor flow path and a partially common removal flow path provided by the precursor distribution and removal system the hardware in the apparatus may be simplified and more efficiently used.

For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught or suggested herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of certain embodiments having reference to the attached figures, the invention not being limited to any particular embodiment(s) disclosed.

BRIEF DESCRIPTION OF THE FIGURES

It will be appreciated that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of illustrated embodiments of the present disclosure.

FIG. 1 depicts a sequential infiltration synthesis apparatus according to an embodiment.

FIG. 2a and FIG. 2b illustrate an infiltration method in accordance with at least one embodiment of the invention for use in the sequential infiltration synthesis apparatus.

FIG. 3 depicts a reaction chamber of a sequential infiltration apparatus according to an embodiment.

FIG. 4 depicts a reaction chamber of a sequential infiltration apparatus according to a further embodiment.

FIG. 5 depicts a reaction chamber of a sequential infiltration apparatus according to an embodiment comprising a batch reactor.

FIG. 6, FIG. 7, FIG. 8, FIG. 9, FIG. 10a , FIG. 10b and FIG. 10c depict different configurations of sequential infiltration synthesis apparatus.

DETAILED DESCRIPTION

Although certain embodiments and examples are disclosed below, it will be understood by those in the art that the invention extends beyond the specifically disclosed embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the invention disclosed should not be limited by the particular disclosed embodiments described below.

FIG. 1 depicts a sequential infiltration synthesis apparatus according to an embodiment. The apparatus comprises a reaction chamber 2 made of a suitable material such as steel, aluminum or quartz. A substrate 12 provided with an infiltrateable material on top may be placed in the reaction chamber 2 on a substrate holder 10 by a substrate handler via a substrate opening (not shown). The reaction chamber 2 forms a chamber closed at one end by a flange, through which gases are introduced via one or more openings provided with at least one (distribution) reaction chamber valve 19 to control opening and closing of said openings. The distribution reaction chamber valve 19 provides access of a fluid distribution portion of the precursor distribution and removal system to the reaction chamber 2.

The precursor distribution and removal system may provide a first or a second precursor 28, 29 to the reaction chamber via the distribution reaction chamber valve 19. The first precursor 28 may be introduced as a gas into the chamber 2 by evaporating a liquid or solid contained in container 30 by first precursor heater 32 to provide adequate vapor pressure for delivery into the chamber 2. The first precursor heater 32 may provide heat to the first precursor in the container 30. Equally a second precursor 29 may be introduced as a gas into the chamber 2 by evaporating a liquid or solid contained in container 31 by a second precursor heater 33 to provide adequate vapor pressure for delivery into the reaction chamber 2.

A distribution buffer tank 18 may be provided in the gas distribution and removal system upstream of the reaction chamber valve 19 to store gas. The buffer tank may have a volume between 0.1 and 15, preferably between 0.3 and 3 and even more preferably between 0.5 and 2 times the volume of the reaction chamber 2. The buffer tank may be filled with the first or second precursor such that when the reaction chamber should be filled with said precursor it is more rapidly filled thereby increasing the throughput of the apparatus. The distribution buffer tank 18 may be heated.

As depicted the flow paths and the buffer tank for the first and second precursor may be partially common however they also may be separated. Separated flow paths with also separate buffer tanks make it possible to load both buffer tanks independently increasing throughput of the apparatus and provided efficient precursor usage. In case of separated flow paths, each flow path may be provided with a separate distribution reaction chamber valve 19.

The precursor distribution and removal system may comprise a purge system to provide a purge gas 34 to the reaction chamber 2 via the purge valve 24 and the distribution reaction chamber valve 19. As depicted the flow paths for purge gas, the first and second precursor may be partially common however they also may be partially or completely separated. In case of separated flow paths, each flow path may be provided with a separate distribution reaction chamber valve 19.

The purge gas may be an inert gas such as nitrogen and may be used to purge the reaction chamber 2. The purge gas may be used to purge the buffer tank 18 as well.

Optionally, a separate exhaust (not depicted) between the buffer tank 18 and the distribution reaction chamber valve 19 may be connected to the pump 39 to purge the buffer tank 18 more effectively while the distribution reaction chamber valve 19 is closed.

Alternatively or additionally, the purge system may be constructed and arranged to provide the purge gas directly in to the reaction chamber 2 via a purge reaction chamber valve (not shown) which directly provides the purge gas in the reaction chamber 2. By providing the purge gas directly in the reaction chamber it becomes possible to use the precursor distribution and removal system to load with precursor while the reaction chamber is purged. In this way it becomes possible to increase throughput. The purge system may be provided with a purge gas buffer chamber to urge more effectively.

The reaction chamber is closed at the other end by a flange which connects to a gas removal part of the precursor distribution and removal system via one or more openings provided with one or more reaction chamber valves 36, such as e.g., a gate valve. A gas removal pump 39 and, optionally, a removal buffer tank 38 may be part of the gas removal portion of the precursor distribution and removal system.

The removal buffer tank 38 may be provided in the gas removal system downstream of the gate valve 36. The removal buffer tank 38 may have a volume between 1 and 30 and preferably between 5 and 15 times the volume of the reaction chamber to suck gas in the removal buffer tank when the reaction chamber valve 36 is opened. The volume of the reaction chamber 2 for substrates having a 300 mm diameter may be for a single substrate reaction chamber 0.5-1 liter volume, for a single substrate reaction chamber with a showerhead above the substrate 3 to 5 liter and for a batch reactor chamber for 25 to 250 substrates 50-200 liter.

The reaction chamber 2 may be provided with an opening (not shown) to provide substrates to the substrate holder 10. A door may be provided to close and open the opening to provide access by a substrate handler to the substrate holder 12. The substrate holder may also form part of the reaction chamber wall and may be moveable to provide access to the substrate holder 10.

The first precursor 28 may be a compound having an element of the infiltration material to be formed in the infiltrateable material on the substrate 12. The first precursor 28 may be provided into the reaction chamber 2 through first precursor valve 20, buffer tank 18 and distribution reaction chamber valve 19. FIG. 1 illustrates a system with two containers 30 and 31, each containing a first and second precursor 28 and 29 respectively. However the type of infiltration material to be formed will determine the number of precursor and containers. For example, if a ternary infiltration material is desired, the apparatus may include three containers and three precursor valves.

Also the containers 30 and 31 may be replaced with other suitable precursor storage means if required. For example if one of the precursors may be solid there may be provided specially adapted containers to accelerate sublimation of the solid precursor. One of the containers 30, 31 may also be provided with a gaseous precursor such that heating is not required.

A sequence controller 40 e.g., a microcontroller may be operably connected to the one or more reaction chamber valves 19, 36, the precursor valves 20, 22 and a purge valve 24. The sequence controller 40 may comprise a memory M to store a program being programmed to enable the apparatus to execute infiltration of the infiltrateable material provided on the substrate 12 in the reaction chamber 2 with the first and second precursor 28, 29. A pressure and/or temperature sensor 26 may monitor the chamber pressure and temperature and may be operably connected with the sequence controller 40 during operation to optimize the process conditions of the infiltration. The program stored in the memory M of the sequence controller 40 may be programmed to sequence the opening and closing of the valves 19, 20, 22, 24 and 36 at the appropriate times to provide and remove the first and second precursor to the reaction chamber 2. The precursor valves 20, 22 may be heated.

The apparatus may be provided with a heating system comprising a first heating element 14 e.g., a heating resistor wire and a heating controller 16 operably connected to temperature sensors 26. One or more of the temperature sensors 26 may be provided with a pressure sensor as well. The heating controller 16 may be operably connected to the sequence controller 40. The temperature sensors 26 may be used to measure the temperature in the reaction chamber 2 and provide feedback to the heating controller 16 about this temperature to adjust the temperature of the heating element 14 to adjust the temperature of the reaction chamber 2.

The heating system 16 may control the temperature from the reaction chamber 2 up to at least one of the reaction chambers valves 19 or 36. The first heating element 14 may therefore be extending along the reaction chamber 2 up to said at least one reaction chamber valve 19 or 36 to heat the reaction chamber 2. The first heating element 14 may heat the reaction chamber 2 and at least one duct between the reaction chamber 2 and said at least one reaction chamber valve 19 or 36. The first heating element may also heat one of the reaction chamber valves 19, 36 to avoid condensation on said valve.

A precursor inflow duct between the (distribution) reaction chamber valve 19 and the reaction chamber 2 may be provided with a portion of the first heating element 14. This portion of the first heating element 14 along the precursor inflow duct may be individually controlled with the temperature sensor 26 extending in the inflow duct and the heating controller 16 to adjust the temperature of the precursor inflow duct.

A precursor removal flow duct between the reaction chamber 2 and the (removal) reaction chamber valve 36 may be provided with a portion of the first heating element 14. This portion of the first heating element 14 along the precursor removal flow duct may be individually controlled with the temperature sensor 26 extending in the precursor removal flow duct and the heating controller 16.

In this way cold spots which may cause condensation in the reaction chamber 2, the precursor inflow duct and the precursor removal flow duct may be avoided. Condensation of the precursor may cause that the precursor is not effectively removable out of the reaction chamber in time and therefore the condensate may react with a subsequent precursor into particles which may contaminate the reaction chamber and the substrate 12. Especially particles in the inflow duct delivering precursors may cause many problems.

The temperature may be set to an optimized process temperature. The speed of the infiltration process may increase with the pressure. Processing at higher pressure is therefore advantageously to maximize throughput but increases the risk of condensation. The boiling temperature of the first or second precursor at the maximum pressure of the first or second precursor in the reaction chamber 2 should be lower than the desired optimized process temperature to avoid condensation. By controlling the temperature from the reaction chamber 2 up to at least one of the reaction chamber valves 19, 36 the risk of condensation can be minimized. It may also be advantageous to control the temperature in the entire flow path from the containers 30 and 31 up to reaction chamber valve 36.

For example if the first or second precursor is trimethylaluminium (TMA) the vapor pressure is:

-   -   20° C.˜9 Torr     -   40° C.˜25 Torr     -   60° C.˜64 Torr     -   80° C.˜149 Torr     -   100° C.˜313 Torr     -   128° C.˜760 Torr

As can be seen from these values the processing pressure can be increased substantially by increasing the temperature in the reaction chamber. However if there is a small portion in the apparatus which is in contact with the precursor and which has a slightly lower temperature there is an immediate risk of condensation of the precursor which is unwanted.

The interaction of a precursor e.g., TMA with the infiltrateable material may be primarily through adsorption and diffusion. The temperature may have a significant effect on the infiltration because the rate of adsorption and diffusion and the equilibrium in an adsorption reaction may be impacted by changes in temperature.

The infiltration process may be optimal at 90° C. while at 120° C. and 150° C. the infiltration is less good for TMA. This may be expected for an adsorption based process. At higher temperature the equilibrium of the adsorption reaction may shift towards separate TMA and polymer species. A process temperature between 20 and 400, preferably between 50 and 150, more preferably between 60 and 110 and most preferably between 65 and 95° C. is therefore preferred.

The heating system may therefore be constructed and arranged to control the temperature of the reaction chamber and a duct from the reaction chamber up to at least their respective reaction chamber valves to between 20 and 450, preferably between 50 and 150, more preferably between 60 and 110 and most preferably between 65 and 95° C. The memory M in the sequence controller may be programmed with a program for the apparatus to reach and/or maintain a pressure of the first or second precursor in the reaction chamber between 0.001 and 1000 Torr, preferably between 0.1 and 400 Torr, more preferably between 1 and 100 Torr and most preferably between 2 and 50 Torr during infiltration to avoid condensation. In this way we create a sufficient safety margin to avoid condensation in the apparatus while having an optimum process temperature and pressure with respect to the use of the precursor TMA.

The apparatus may comprise a direct liquid injector (DLI) comprising a liquid flow controller and a vaporizer. The liquid flow controller may control a liquid flow to an vaporizer to evaporate the first or second precursor. There may not be a need to heat the liquid flow between the flow controller and the vaporizer. The vaporizer may be heated to evaporate the first or second precursor. The heating system may be constructed and arranged to control the temperature from the reaction chamber 2 up to the vaporizer to at least a boiling temperature of the first or second precursor at the pressure of the first or second precursor in the reaction chamber 2 to avoid condensation. The vaporizer may be constructed and arranged in the reaction chamber to directly provide the evaporated precursors in the reaction chamber. The vaporizer may also be constructed and arranged in the precursor distribution and removal system of the apparatus.

The precursor distribution and removal system of the apparatus may comprise at least one buffer tank 18, 38 provided in the precursor distribution and removal system. The buffer tank may be a distribution buffer tank 18 positioned upstream of the reaction chamber 2 to store gaseous first or second precursor 28, 29 and has a volume between 0.1 and 10 preferably between 0.3 and 3 and even more preferably between 0.5 and 2 times the volume of the reaction chamber 2. The volume of the reaction chamber 2 for substrates having a 300 mm diameter may be for a single substrate reaction chamber 0.5-1 liter volume, for a single substrate reaction chamber with a showerhead above the substrate 3 to 5 liter and for a batch reactor chamber for 25 to 250 substrates 50-200 liter.

The distribution buffer tank 18 may be provided with a direct liquid injector (DLI) vaporizer to directly inject the gaseous precursor in the buffer tank. The distribution buffer tank 18 may comprise a flexible bellow to accommodate different volumes in the buffer tank. The distribution buffer tank 18 may be provided in or near the top of the reaction chamber 2 to have a short delivery line to the reaction chamber 2 and at the same time it may be heated by the reaction chamber.

The apparatus may comprise a second heating element 17 to control the temperature of the precursor buffer tank 18 and/or the ducts in the fluid distribution part of the precursor distribution and removal system. The temperature of these parts may be controlled to 0 to 50, more preferably 0.1 to 20, even most preferably 0.2 to 10° C. above the temperature of the reaction chamber 2. The second heating element 17 may be controlled by the heating controller 16. A second temperature/pressure sensor (not depicted) may be provided to the precursor buffer tank 18 and or the and/or the ducts in the fluid distribution part and operably connected to the heating controller 16 to enhance control. By having the buffer tank 18 at a higher temperature than the reactor chamber 2 it becomes possible to maintain a higher vapor pressure in the buffer tank 18 for the precursor so that a smaller size buffer tank is necessary to fill after opening distribution reaction chamber valve 19 the reactor chamber 2 in a short time span.

The first and second heating elements 14 and 17 may be a resistor wire being wound around the relevant portions of the apparatus. With a good temperature insulation and a relatively low working temperature around 90° C. such an embodiment may work. The first and second heating element 14, 17 may be multizone heating elements with multiple temperature sensor to control the temperature in every part of the tool more precisely.

The precursor distribution and removal system may comprise a bubbler for providing the precursor. The bubbler may provide a non-continuous precursor flow having pulses of the first precursor of 0.1 to 200, preferably 1 to 3 seconds alternating with pulses of a mixing gas for 0.01 to 2, preferably 0.3 to 1 seconds.

The precursor distribution and removal system may be provided with a direct liquid injector (DLI) vaporizer to directly inject the gaseous precursor in the reaction chamber 2, in the distribution buffer tank 18 or in other duct of the precursor distribution and removal system upstream of the distribution reaction chamber valve 19.

The precursor distribution and removal system may have a removal buffer tank 38 provided in the precursor distribution and removal system downstream of the reaction chamber after the removal reaction chamber valve 36 but before the removal pump 39. The removal buffer tank may have a volume between 1 and 20 and preferably between 5 and 15 times the volume of the reaction chamber to suck gas in the buffer tank when the removal reaction chamber valve 36 is opened.

Referring to FIG. 1, during a typical operation, the first precursor 28 is infiltrated in the infiltrateable material on the substrate by exposure to the first precursor 28 in vapor phase from the container 30. The first precursor 28 may react with the infiltrateable material on the substrate and become a chemi-sorbed or physi-sorbed derivative infiltrated in the infiltrateable material on the substrate. Subsequently the second precursor 29 is infiltrated in the infiltrateable material on the substrate by exposure to the second precursor 29 in vapor phase from the container 31. The second precursor 29 may react with the chemi-sorbed or physi-sorbed derivative of the first precursor 28 infiltrated in the infiltrateable material on the substrate to become the final infiltration material.

The containers 30, 31 for storing a first or second precursor be constructed and arranged to store an alkyl compound of aluminum selected from the group consisting of trimethyl aluminum (TMA), triethyl aluminum (TEA), and dimethylaluminumhydride (DMAH).

The containers 30, 31 may be constructed and arranged to store a first or second precursor such as titanium(IV)chloride (TiCl), tantalum(V)chloride (TaCl5), and/or niobium chloride (NbCl5).

For infiltrating zirconium or hafnium the containers 30, 31 may be constructed and arranged to store a Zr or Hf precursor. The Zr or Hf precursor may comprise metalorganic, organometallic or halide precursor. In some embodiments the precursor is a halide. In some other embodiments the precursor is alkylamine compound of Hf or Zr, such as TEMAZ or TEMAH.

The containers 30, 31 may be constructed and arranged to store a first or second precursor such as an oxidant chosen from the group comprising water, ozone, hydrogenperoxide, ammonia and hydrazine.

The apparatus may comprise a first container 31 for containing the first or second precursor such as an aluminum or boron hydrocarbon compound preferably selected from the group consisting of trimethyl aluminum (TMA), triethyl aluminum (TEA), dimethylaluminumhydride (DMAH) dimethylethylaminealane (DMEAA), trimethylaminealane (TEAA), N-methylpyrroridinealane (MPA), tri-isobutylaluminum (TIBA), tritertbutylaluminum (TTBA) trimethylboron and triethylboron and a second container 31 for containing the other of the first and second precursor such as a metal halide preferable from the group consisting of titanium(IV)chloride (TiCl), tantalum(V)chloride (TaCl5), and niobium chloride (NbCl5). The latter may be preferable for infiltrating metal carbide material.

FIGS. 2a and b illustrate an infiltration method in accordance with at least one embodiment of the invention for use in the apparatus of FIG. 1. The method includes a first step 50 of providing a substrate into a reaction chamber with a substrate handler, the substrate having at least one infiltrateable material on the substrate.

The infiltrateable material may be porous. Porosity may be measured by measuring the void spaces in the infiltrateable material as a fraction of the total volume of the infiltrateable material and may have a value between 0 and 1. The infiltrateable material may be qualified as porous if the fraction of void spaces over the total volume is larger than 0.1, larger than 0.2 or even larger than 0.3.

The infiltrateable material may be an hardmask material, for example, comprise a spin on glass or spin on carbon layer, a silicon nitride layer, an anti-reflective-coating or an amorphous carbon film. The spin on glass or spin on carbon layer may be provided by spinning a glass or carbon layer on the substrate to provide the hardmask material. Further, the hardmask material may comprise SiCOH, or SiOC.

In an embodiment the infiltrateable material may be a patterned layer for example a patterned (photo)resist layer. The resist layer may be annealed. The anneal step may have a purpose of degassing moisture or other contaminants from the resist, hardening the resist, selectively burning away portions of the resist from the substrate surface or creating the required porosity.

In an embodiment the patterned layer may be provided by having a block copolymer film and promoting directed self-assembly of the block copolymer film to form the patterned layer. Infiltrating such patterned layer may improve the quality of such patterned layer. The block copolymer film may, for example, have a low etch resistance and by infiltrating the pattern in the copolymer the etch resistance of the pattern may be improved.

In an embodiment the patterned layer may be provided by having a photoresist being exposed with a lithographic apparatus. Infiltrating such patterned layer may improve the quality of such patterned layer. The patterned photoresist layer may, for example, have a low etch resistance and by infiltrating the patterned photoresist the etch resistance of the pattern may be improved.

After the substrate is positioned in the reaction chamber 2 in FIG. 1 during step 50 in FIG. 2 the reaction chamber and substrate may be cleaned by the removal pump 39 evacuating the reaction chamber 2. Optionally a purge gas 34 may be provided with the purge system to flush the reaction chamber 2 via the purge valve 24 and the distribution reaction chamber valve 19. The reaction chamber 2 may be heated to enhance outgassing.

The program in the memory M may be programmed to activate the precursor distribution and removal system to remove gas from the reaction chamber 2 and to provide purge gas with the purge system to have the reaction chamber purged for 1 to 4000 seconds, preferably 100 to 2000 seconds before the infiltration is started. The program in the memory M may be programmed to activate the heater system 16 to heat the reaction chamber 2 to a temperature between 20 and 450° C., preferably between 50 and 150° C. and most preferably between 70 and 100° C. to enhance outgassing of contaminants.

Subsequently, the method comprises an infiltration method 51 in which the infiltrateable material may be infiltrated with the infiltration material during one or more infiltration cycles. Each infiltration cycle may comprise the following steps:

Step 52 comprises providing a first precursor to the infiltration material on the substrate in the reaction chamber for a first period T1. The memory M of the sequence controller 40 may be provided with a program which when executed on the processor of the sequence controller 40 makes the infiltration apparatus close the purging valve 24 and the distribution reaction chamber valve 19 and builds up first precursor in the duct of the precursor distribution and removal system upstream of the distribution reaction chamber valve 19 by opening the first precursor valve 20 and evaporating the first precursor 28 from the first container 30 by having the first precursor temperature controller 32 activated to heat the container 32. The first precursor may be stored in the buffer tank 18. The heating element 17 may be controlled by the heating controller 16 to heat the duct sufficiently to keep a high vapor concentration in the duct and buffer tank 18 of the first precursor.

Then the program in the memory M of the sequence controller 40 may be programmed to execute the opening of the valve 20 for a short period of time to deliver the first precursor 28 to the reactor chamber 2. This may be done with the removal reaction chamber valve 36 opened and the removal pump activated for a flush period FP to flush the reaction chamber 2 with the first precursor. The flush period FP may also be omitted. When the reaction chamber 2 is constructed and arranged to accommodate a single substrate the program in the memory may be programmed to activate the first precursor flow controller for the flush period FP between 1 to 60, preferably between 2 and 30 seconds. When the reaction chamber is constructed and arranged to accommodate 2 to 25 substrates the program in the memory may be programmed to have the flush period between 1 to 100, preferably between 2 and 50 seconds. When the reaction chamber is constructed and arranged to accommodate 26 to 200 substrates and the program in the memory is programmed to have the flush period FP between 1 to 100, preferably between 5 and 50 seconds.

The first precursor may also be provided to the reactor chamber 2 with the precursor distribution and removal system while not removing any precursor with the removal pump 39 for a load period LP by closing the removal reaction chamber valve 36 by the program installed in a memory M of the sequence controller 40. This results in a pressure buildup of the first precursor in the reaction chamber 2. This build up may be terminated by the sequence controller 40 when the pressure of the first or second precursor in the reaction chamber 2 reaches a maximum desired infiltration pressure. Alternatively, there may be a pressure release valve which opens when the pressure in the reaction chamber increases above a predetermined maximum which may also end the pressure load period LP.

Subsequently the first precursor may be maintained residing stationary in the reaction chamber 2 while having the precursor distribution and removal system not providing or removing any precursor for a soak period SP. This may be done by the sequence controller 40 closing the reactor chamber valves 19 and 36 in accordance with the program stored in the memory M. When the reaction chamber 12 is constructed and arranged to accommodate a single substrate the program in the memory M may be programmed to activate the first precursor flow controller for the load period LP between 1 to 3000, preferably between 3 and 1000, more preferably between 5 to 500 seconds; and the soak period SP between 10 to 9000, preferably between 50 and 5000 seconds and more preferably between 100 and 1000 seconds. When the reaction chamber 12 is constructed and arranged to accommodate 2 to 25 substrates the program in the memory sequence controller may be programmed with the load period LP between 1 to 3000, preferably between 3 and 1000, more preferably between 5 to 500 seconds; and the soak period SP between 10 to 12000, preferably between 15 and 6000 seconds and more preferably between 20 and 1000 seconds. When the reaction chamber 12 is constructed and arranged to accommodate 26 to 200 substrates the program in the memory M may be programmed to have the load period LP between 1 to 3000, preferably between 3 and 1000, more preferably 5 to 500 seconds; and the soak period SP between 10 to 14000, preferably between 50 and 9000 seconds, more preferably between 100 and 5000 and most preferably between 100 and 800 seconds.

The first period T1 therefore may comprise a flush period FP, a load period LP, and/or a soak period SP. During the whole period T1 the first precursor may infiltrate and absorb in the infiltrateable material.

The memory M of the sequence controller 40 may be programmed with the program when executed on a processor of the sequence controller making the infiltration apparatus to provide the first precursor for the first period T1 between 1 to 20000, preferably between 20 to 6000, more preferably between 50 and 4000, and most preferably between 100 and 2000 seconds in step 52. In this way a deep infiltration of the first precursor in the infiltrateable material may be assured.

In step 53 a portion of the first precursor is removed for a second period T2. The sequence controller 40 may open the removal reaction chamber valve 36 to remove first precursor with the vacuum pump 38 from the reaction chamber 2. Additionally a purge gas 34 may be provided with the purge system to flush the reaction chamber 2 by opening the purge valve 24 and the distribution reaction chamber valve 19 with the sequence controller 40. The buffer tank 18 may be used to provide the purge gas more rapidly in the reaction chamber 2 by storing purge gas in the buffer tank.

The program in the memory M of the sequence flow controller 40 may be programmed with a program when executed on a processor of the sequence controller 40 will make the infiltration apparatus to control the second duration T2 of removing the portion of the first precursor. The program in the memory M may be programmed with the second period T2 between 1 to 20000, preferably between 20 to 6000, more preferably between 50 and 4000, and most preferably between 100 and 2000 seconds.

In step 54 the second precursor is provided in the reaction chamber 2 by the sequence controller 40 activating the precursor distribution and removal system to provide and maintain the second precursor for a third duration T3 in the reaction chamber. The memory M of the sequence controller 40 may be programmed to close the purging valve 24 and the distribution reaction chamber valve 19 and building up second precursor in the duct of the precursor distribution and removal system upstream of the distribution reaction chamber valve 19 by opening the second precursor valve 22 and evaporating the second precursor 29 from the second container 31 by having the second precursor temperature controller 33 activated to heat the second container 31. The second precursor may be stored in the buffer tank 28. The heating element 17 may be controlled by the heating controller 16 to heat the duct sufficiently to keep a high vapor concentration in the duct and buffer tank 18. Then the memory M of the sequence controller 40 may be programmed to open valve 20 for a short period of time to deliver the second precursor 28 to the reactor chamber 2.

The flush period FP, load period LP, and soak period SP have been described in conjunction with the first precursor. The memory M of the sequence controller may be provided with a program when executed on the processor of the sequence controller 40 will make the infiltration apparatus run the third period 54 with a flush period FP, a load period LP, and/or a soak period SP of the second precursor as explained in FIG. 2b . During the whole third period T3 the second precursor may infiltrate the infiltrateable material and react with the absorbed first precursor derivative in the infiltrateable material. Resulting in a reaction with the absorbed first precursor derivative resulting reinforcement of the infiltrateable material with infiltrated material.

Optionally the infiltration cycle may have a step 55 in which a portion of the second precursor may be removed for a fourth period T4. The sequence controller 40 may open the removal reaction chamber valve 36 to remove first precursor with the vacuum pump 38 from the reaction chamber 2. Additionally a purge gas 34 may be provided with the purge system to flush the reaction chamber 2 by opening the purge valve 24 and the distribution reaction chamber valve 19 with the sequence controller 40.

The memory M of the sequence controller may be programmed so that when the program is executed on a processor of the sequence controller 40 of an infiltration apparatus the infiltration sequence may be repeated N times, wherein N is between 1 to 20, preferably 3 to 15 and most preferably between 6 to 12. The precursors 28 and 29 may be chosen such that the precursors form a metal or dielectric infiltration material in the infiltrateable material.

The first precursor and the second precursor may be utilized together in the apparatus of FIG. 1 to infiltrate the infiltrateable material according to the program of FIGS. 2a and 2b with aluminum oxide (Al2O3), silicon oxide, (SiO2), silicon nitride (SiN), silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon carbide (SiC), titanium carbide (TiC), aluminum nitride (AlN), titanium nitride (TiN), tantalum nitride (TaN), tungsten (W), cobalt (Co), titanium oxide (TiO2), tantalum oxide (Ta2O5), zirconium oxide (ZrO2), or hafnium oxide (HfO2).

Optionally, the infiltration material such as a metal or dielectric may be deposed on top of the whole volume of the infiltrateable material with the infiltration apparatus as well. This may, for example, be done if the infiltrateable material is patterned to make the pattern wider and more etch resistant.

FIG. 3 depicts a sequential infiltration apparatus according to a further embodiment. The reaction chamber 2 is provided with a substrate 12 on a substrate holder 10. The precursor distribution and removal system provides the first or second precursors from one side of the reaction chamber 2 via entry port 66 to the substrate 12. The entry port 66 may be provided with a buffer tank 18 and closeable with a valve 19. An exit port 67 is provided to the distribution and removal system to remove the precursor from the reaction chamber 2 on the other side. In this configuration the reaction chamber 2 will be a cross flow reaction chamber in which precursors latterly flow over the substrate.

The substrate holder 10 for holding the substrate 12 may be moveable up and down. The substrate holder 10 may be moveable underneath an edge 68 of the top portion of the reaction chamber 2 to allow a substrate handler (not depicted) to provide or remove a substrate from the substrate holder 10. By moving it up the reaction chamber can be closed again. The substrate holder 10 may comprise a third heating element for heating of the substrate 12.

An advantage of the embodiment according to FIG. 3 is that the reaction chamber 2 may have a small volume of 0.5-1 liter for a single substrate reaction chamber 2. The small volume making it possible to have a low precursor usage. The space between substrate and the top of the reaction chamber may therefore be less than 1 centimeter, preferably less than 5 mm and most preferably less than 3 mm.

FIG. 4 depicts a sequential infiltration apparatus according to a further embodiment. The reaction chamber 2 comprises a showerhead 69. The showerhead 69 may be provided in the top portion of the reaction chamber 2. The showerhead 61 may be connected with the precursor distribution and removal system to provide the first or second precursors 28, 29 to the surface of the substrate 12 directly. The precursor distribution and removal system may remove the first or second precursors 28, 29 by the opening 67. The purge system may also be connected to the showerhead 69 to purge the reaction chamber 2.

The showerhead 69 may also be connected with the precursor distribution and removal system to remove the first or second precursors from the reaction chamber 2. The opening 67 may be connected to the purge system to purge the reaction chamber 2 in such case.

The substrate holder 10 for holding the substrate 12 may be moveable up and down. The substrate holder 10 may comprise a third heating element for heating of the substrate 12. An advantage of this embodiment is that the showerhead rapidly provides and removes precursor from the surface of the substrate while the volume still is acceptable between 2 to 5 liter, preferably 3 to 4 liter.

FIGS. 5, 6, 7, 8 and 10 a-10 c show different configurations of sequential infiltration synthesis apparatus. The sequential infiltration synthesis apparatus according to FIGS. 5, 6, 7, 8 and 10 may use the same precursor distribution and removal system as explained in conjunction with FIGS. 1 and 2.

FIG. 5 depicts a sequential infiltration apparatus according to a further embodiment. The apparatus comprises a batch reactor chamber 70 for 25 to 250 substrates with a volume of 50-200 liter. The substrates may be loaded in a boat 71 which is provided with substrate holders to accommodate the 25 to 250 substrates with a substrate handler. The boat 71 with the substrates may be moved in the reaction chamber 70 in once from underneath. The bottom part 71A of the boat 70 may seal the reaction chamber 70. A heating element 40 may be provided to control the temperature of the reaction chamber 70. First and second precursor may be provided with the inlet 72 and may be removed via outlet 73 of the precursor distribution and removal system. Valves may be used to control the gas flow and care should be taken to ensure that the evaporated precursors are kept at a temperature above their boiling temperature in the reaction chamber 70. This may be done by having the heating element to control the temperature in the inlet 72 and the outlet 73 as well up to the valves (e.g., reaction chamber valve 36).

In case the apparatus is provided with a direct liquid injector (DLI) comprising a liquid flow controller and a vaporizer, the liquid flow controller may control a liquid flow to the vaporizer which evaporates the first or second precursor. There may not be a need to heat the liquid flow between the flow controller and the vaporizer. The vaporizer may be heated to evaporate the first or second precursor directly.

The vaporizer may be provided in the batch reactor chamber to directly provide the first or second precursor in the chamber. A batch reactor makes it possible to infiltrate a large number of substrates at the same time improving the throughput of the apparatus.

FIGS. 6, 7, 8 and 10 a-10 c show different configurations of sequential infiltration synthesis apparatus. The sequential infiltration synthesis apparatus according to FIGS. 6, 7, and 8 may use the reaction chamber 2 as described in conjunction with FIG. 3 or 4.

Shown are cassette loading stations 74 for loading cassettes (e.g., Front Opening Unified Pod's FOUP) with multiple substrates. A first substrate handler 75 is used to move the substrates from the cassettes to an intermediate loading station 76. Subsequently, a second substrate handler 77 is used to move the substrates from the intermediate loading station 76 to a processing station provided with the substrate holder 10. In FIG. 6 a single substrate holder 12 is accessible by the second substrate holder 77 for a single substrate which can be processed in the reaction chamber 2. In the embodiment of FIG. 6 four substrates can be processed simultaneously.

A partially common precursor distribution and removal system to provide to and remove from at least two reaction chambers the first or second precursor is provided. The partially common precursor distribution and removal system may share the reaction chamber valves. The reaction chamber valves may also be separate for each reaction chamber. The common part of the precursor distribution and removal system may be further provided downstream of the (distribution) reaction chamber valve 19 and downstream of the (removal) reaction chamber valve 36 as explained in conjunction with FIG. 1. In this way economical use of the precursor distribution and removal system can be made.

Heating elements may be provided to heat the reaction chamber 2, the substrate holder 10 and/or a duct in the precursor distribution and removal system up to any of the reaction chamber valves. At least one buffer tank may be provided in the precursor distribution and removal system.

In the embodiment of FIGS. 7 and 8 the processing stations are provided with multiple substrate holders 10 and are provided with a moveable (e.g., rotatable) body 78 (alternatively a rotating substrate support frame may be used) and by rotating this body 78 (or the support frame) all the substrate holders 10 can be provided with substrates by the second substrate handler 77. The substrate holders 10 can be moved upwards to close and form a reaction chamber 2. Alternatively or additionally a door 80 may be provided to close the space with the reaction chamber(s).

In the embodiment of FIG. 7 it may be eight substrate holders that form eight reaction chambers processing a single substrate or it may be eight substrate holders that form two shared reaction chambers each shared reaction chamber processing four substrates.

In the embodiment of FIG. 7 it may be possible to dedicate the substrates (normally 25) in a particular FOUP on the cassette loading station 74 to a particular body 78 so that all the substrates in a FOUP are processed on the same body 78 and the reaction chamber (relating thereto). The advantage being that if there is an error found in the processing of one FOUP it is known in which part of the infiltration apparatus it occurred. In the embodiment of FIG. 7 two times four substrates can be processed simultaneously.

In the embodiment of FIG. 8 the first and second substrate handler 75, 77 may be provided with a dual substrate support to handle two substrates at the same time to increase throughput. The moveable boy 78 can be rotated around axis 82 to provide access of the second substrate handler 78 to the different substrate holders 10. In the embodiment of FIG. 8 it may be sixteen substrate holders 10 that form sixteen reaction chambers processing a single substrate or it may be sixteen substrate holders 10 that form four shared reaction chambers each shared reaction chamber processing four substrates. In the embodiment of FIG. 8 four times four substrates can be processed simultaneously giving the apparatus a high productivity.

FIG. 9 discloses a cross section of a processing station of the embodiments of FIGS. 7 and 8. A moveable body 78 is provided for holding two or more (e.g., 3, 4, 5, or 6) substrates 12. The moveable body 78 can be moved upwards against the sealing 81 to close and create two or more reaction chambers 2. The moveable body 78 can be rotated around axis 82 to provide access of the second substrate handler 78 to different substrates 12 on the substrate holder 10.

A partially common precursor distribution and removal system to provide to and remove from the at least two reaction chambers 2 the first or second precursor is provided. The partially common precursor distribution and removal system shares the reaction chamber valves 19 and 36. The common part of the precursor distribution and removal system is further provided upstream of the (distribution) reaction chamber valve 19 and downstream of the (removal) reaction chamber valve 36 as explained in conjunction with FIG. 1. In this way economical use of the precursor distribution and removal system can be made.

Heating elements may be provided to heat the reaction chamber 2, the substrate holder 10 and/or a duct in the precursor distribution and removal system up to any of the reaction chamber valves 19, 36. At least one buffer tank may be provided in the precursor distribution and removal system.

In an embodiment not shown five processing stations with each five substrate holders may be provided to process simultaneously a complete FOUP with 25 substrates guaranteeing short processing times for a complete FOUP.

FIGS. 10a 10b and 10c depict a further embodiment according to the invention. In this embodiment a processing station 90 is provided with slits 91 which can function as a substrate holder 10 (see FIG. 10 c which shows a cross section through the slit 91). Cassette loading stations 74 are provided for loading cassettes (e.g., Front Opening Unified Pod's FOUP) with multiple substrates. A first substrate handler (not shown but similar to first substrate handlers 75 in FIGS. 6 and 7) may be used to move the substrates from the cassettes to an intermediate loading station (not shown but similar to intermediate loading station 76 in FIGS. 6 and 7). A second substrate handler (not shown but similar to second substrate handlers 77 in FIGS. 6 and 7) may provide substrates to the slits 91 from the intermediate loading station. A door may close the slits 91 to create a reaction chamber and the substrates may be processed at the processing station 90.

A partially common precursor distribution and removal system 93 may be provided to provide and remove from all the substrates in the slits 91 the first or second precursor simultaneously. Five substrates may be processed simultaneously in processing station 90 which has the advantage that a complete FOUP with 25 substrates at the cassette station 74 can be processed in five processing stations 90. Since the apparatus has eight processing station 90 it may be possible to process forty substrates simultaneously guaranteeing short processing times for a complete FOUP.

First heating elements may be provided to heat the reaction chamber in the slits 91 in the processing station 90 and/or a duct in the precursor distribution and removal system 93. Advantageously this may be done up to any of the reaction chamber valves in the precursor distribution and removal system 93. At least one buffer tank may be provided in the precursor distribution and removal system 93.

The particular implementations shown and described are illustrative of the invention and its best mode and are not intended to otherwise limit the scope of the aspects and implementations in any way. Indeed, for the sake of brevity, conventional manufacturing, connection, preparation, and other functional aspects of the system may not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and/or physical couplings between the various elements. Many alternative or additional functional relationship or physical connections may be present in the practical system, and/or may be absent in some embodiments.

It is to be understood that the configurations and/or approaches described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense, because numerous variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. Thus, the various acts illustrated may be performed in the sequence illustrated, in other sequences, or omitted in some cases.

The subject matter of the present disclosure includes all novel and nonobvious combinations and sub-combinations of the various processes, apparatus, systems, and configurations, and other features, functions, acts, and/or properties disclosed herein, as well as any and all equivalents thereof. 

What is claimed is:
 1. A sequential infiltration synthesis apparatus comprising: a reaction chamber provided with a substrate holder to hold at least one substrate; a precursor distribution and removal system comprising one or more reaction chamber valves to provide to and remove from the reaction chamber a gaseous first and/or second precursor; and, a sequence controller operably connected to the one or more reaction chamber valves and being programmed to enable sequential infiltration of an infiltrateable material provided on the substrate in the reaction chamber with the gaseous first and second precursor, wherein the apparatus is provided with a heating system constructed and arranged to control the temperature of the reaction chamber up to at least one of the reaction chambers valves.
 2. The apparatus according to claim 1, wherein the apparatus is constructed and arranged to maintain a pressure of the first or second precursor in the reaction chamber between 0.001 and 1000 Torr and the heating system is constructed and arranged to control the temperature of the reaction chamber up to at least one of the reaction chamber valves to at least a boiling temperature of the first or second precursor at the pressure of the first or second precursor in the reaction chamber between 20 and 450° C. during infiltration.
 3. The apparatus according to claim 1, wherein at least one reaction chamber valve comprises a gate valve, a pressure relief valve, or a pump to control the flow of a gas and the heating system is constructed and arranged to control the temperature in the reaction chamber up to the reaction chamber valve.
 4. The apparatus according to claim 1, wherein at least one reaction chamber valve comprises a liquid flow controller in a liquid injection system to control a liquid flow to a vaporizer to evaporate the first or second precursor and the heating system is constructed and arranged to control the temperature from the vaporizer to the reaction chamber to at least a boiling temperature of the first or second precursor at the pressure of the first or second precursor in the reaction chamber.
 5. The apparatus according to claim 1, wherein the precursor distribution and removal system comprises a duct between the reaction chamber and at least one reaction chamber valve to provide or remove a gaseous precursor and the heating system is provided around the duct to control the temperature of the duct.
 6. The apparatus according to claim 1, wherein the precursor distribution and removal system comprises a second heating system constructed and arranged to control the temperature of the precursors to a pre temperature 0 to 50° C. above the temperature of the reaction chamber before providing the first or second precursor in the reaction chamber.
 7. The apparatus according to claim 1, wherein the precursor distribution and removal system is provided with a purge system to purge the reaction chamber with a purge gas.
 8. The apparatus according to claim 1, wherein the sequence controller comprises a memory being programmed to enable the apparatus to execute infiltration during N infiltration cycles comprising: providing the first precursor in the reaction chamber by the precursor distribution and removal system to provide and maintain the first precursor for a first duration of T1 in the reaction chamber; removing a portion of the first precursor from the substrate for at least a second duration of T2 by activating the precursor distribution and removal system; providing the second precursor in the reaction chamber by activating the precursor distribution and removal system to provide and maintain the second precursor for a third duration T3 in the reaction chamber.
 9. The apparatus according to claim 8, wherein the sequence controller is programmed to: provide the first precursor to the reactor chamber with the precursor distribution and removal system while not removing any precursor for a load period LP; and leave the first precursor in the reaction chamber while having the precursor distribution and removal system deactivated for a soak period SP.
 10. The apparatus according to claim 9, wherein the sequence controller is programmed to: provide the first precursor to the reactor chamber with the precursor distribution and removal system while removing any precursor for a flush period FP before and/or after the load period LP.
 11. The apparatus according to claim 9, wherein the sequence controller is programmed to: terminate the load period LP when the pressure of the first or second precursor in the reaction chamber reaches a desired infiltration pressure.
 12. The apparatus according to claim 8, wherein the sequence flow controller is programmed to control the precursor distribution and removal system to have the duration T1 of providing the first precursor longer than the second duration T2 of removing the portion of the first precursor from the substrate.
 13. A sequential infiltration synthesis apparatus comprising: a reaction chamber provided with a substrate holder to hold at least one substrate; a precursor distribution and removal system comprising one or more reaction chamber valves to provide to and remove from the reaction chamber a gaseous first or second precursor; and, a sequence controller operably connected to the one or more reaction chamber valves and being programmed to enable sequential infiltration of an infiltrateable material provided on the substrate in the reaction chamber with the gaseous first and second precursor, wherein the apparatus comprises at least one buffer tank provided in the precursor distribution and removal system.
 14. The apparatus according to claim 13, wherein the buffer tank is a distribution buffer tank positioned upstream of the reaction chamber to store first or second precursor and has a volume between 0.1 and 15 times the volume of the reaction chamber.
 15. The apparatus according to claim 13, wherein the apparatus is provided with a heating system constructed and arranged to control the temperature of the reaction chamber to a process temperature and the buffer tank is provided with a second heating system constructed and arranged to control the temperature of the buffer tank to a buffer tank temperature.
 16. The apparatus according to claim 15, wherein the buffer tank temperature is 0 to 50° C. above the process temperature.
 17. The apparatus according to claim 15, wherein the process temperature is between 20 and 450° C. and the sequence controller is constructed and arranged to maintain a pressure in the reaction chamber between 0.001 and 1000 Torr.
 18. The apparatus according to claim 13, wherein the buffer tank is provided with a direct liquid injector (DLI) vaporizer to directly inject the respective precursor in the buffer tank.
 19. The apparatus according to claim 13, wherein the buffer tank comprises a flexible bellow to accommodate different volumes in the buffer tank.
 20. The apparatus according to claim 13, wherein the buffer tank is provided in or near the top of the reaction chamber.
 21. The apparatus according to claim 13, wherein the apparatus comprises a removal buffer tank provided in the precursor distribution and removal system downstream of the reaction chamber and the removal buffer tank has a volume between 1 and 20 times the volume of the reaction chamber to accommodate gas in the buffer tank when one of the reaction chamber valves is opened.
 22. The apparatus according to claim 13, wherein the apparatus comprises a bubbler for providing a non-continuous first precursor flow having pulses of the first precursor of 0.5 to 20, alternating with pulses of an inert gas for 0.1 to 5 seconds for the first duration T1.
 23. The apparatus according to claim 13, wherein the reaction chamber comprises a showerhead provided in the top portion of the reaction chamber and connected with the precursor distribution and removal system to provide the first or second precursors to the surface of the substrate.
 24. The apparatus according to claim 23, wherein the gas distribution system comprises a purge system which is connectable with the shower head to purge the reaction chamber.
 25. A sequential infiltration synthesis apparatus comprising: a reaction chamber provided with a substrate holder to hold at least one substrate; a precursor distribution and removal system comprising one or more reaction chamber valves to provide to and remove from the reaction chamber a gaseous first or second precursor; and, a sequence controller operably connected to the one or more valves and being programmed to enable sequential infiltration of an infiltrateable material provided on the substrate in the reaction chamber with the gaseous first and second precursor, wherein the apparatus comprises at least two reaction chambers each chamber constructed and arranged to accommodate a single substrate and the precursor distribution and removal system is a partially common precursor distribution and precursor distribution and removal system removal system to provide to and remove from the at least two reaction chambers the first or second precursor simultaneously. 